Specialist Registered Dietitian in Belfast Supporting Gut Health, Weight Loss & Hormonal Health

BMI Calculator

How to Check your BMI using a BMI Calculator

You can use a BMI calculator to check whether you fall within a healthy weight range. To do this, you will need your current weight in kilograms (kg) and your height in centimetres (cm).

The BMI calculator uses these measurements to produce a number called your Body Mass Index (BMI). This number helps indicate whether your weight is within a healthy range for your height.

You can calculate your Body Mass Index using the BMI calculator below.

Height
cm.
Please enter value between 125 and 225.
Weight
kg.
Please enter value between 10.0 and 500.0 ( one decimal ).
Height
ft.
in.
Please enter value between 4.2 and 7.3
Weight
lb.
st.
Please enter value between 22.0 and 1000.0 ( one decimal ).
Calculate BMI
Use this calculator to check your body mass index (BMI), which can be a helpful tool in determining your weight category. Or, use it to calculate your child’s BMI.

Understanding your BMI Result

Underweight

Being underweight may be a sign that you are not eating enough, or that an underlying health issue may be affecting you. If your BMI result falls into this category, we can support you with personalised nutritional advice to help bring your weight back into a healthier range.

We create a detailed programme tailored to you, including recipes and a shopping list, to make the process as simple and practical as possible.

Healthy Weight

Reaching a healthy weight range is fantastic. However, it is important to remember that health is not only about a number on the scale. Instead, it involves finding a balance that suits your individual body composition, including fat stores and muscle mass.

Maintaining this balance is important because it can help reduce the risk of developing future health concerns.

Higher weight range

If your BMI result places you in a higher weight range, there is a good chance you may have tried several times to change this. Many people find weight management challenging without the right guidance and support.

Weight management is a specialist area at 121 Dietitian. Over the years, we have helped thousands of people make sustainable changes that allow them to improve their health while still enjoying life. Typically, success comes from combining a personalised nutrition plan with appropriate physical activity.

BMI in the obese range

If your BMI falls into the obese range, the idea of losing weight can sometimes feel overwhelming or isolating. Like many people in this category, you may have tried different approaches or general programmes before and found yourself returning to your previous weight.

However, with the right support and structure, lasting change is possible. At 121 Dietitian, we work closely with you to ensure your plan is sustainable and suited to your health needs.

Improving long-term health often takes time. In many cases, it may take several months to optimise different aspects of your health before meaningful and sustainable weight loss occurs. For example, blood tests may sometimes be recommended, and we will guide you through this if needed.

You will receive a personalised programme and ongoing support, with monitoring for up to a year to help you stay on track and achieve your goals.

BMI for black, asian and other minority ethnic groups

Research shows that individuals from Black, Asian and other minority ethnic groups may have a higher risk of developing certain long-term health conditions, including type 2 diabetes.

For adults from these groups, health risks may increase at lower BMI levels:

  • BMI of 23 or above: increased health risk
  • BMI of 27.5 or above: high health risk

Need help understanding your BMI?

If you have any concerns about your BMI, diet, or nutrition, we would be happy to support you.

You can also explore our blog: ‘Weight Loss – Are You Struggling?’ and How to lose weight for good!

If you would like personalised guidance, you can book a 121 Dietitian programme using the link below.